The bidirectional longitudinal association between academic performance and cardiovascular disease risk factors in adolescents.

INTRODUCTION: The limited prior research examining the association between academic performance and cardiovascular disease (CVD) risk factors in youth did not explore the reciprocal association between these constructs, and analyzed CVD risk factors individually. Thus, the aim of the present study was to explore the bidirectional longitudinal association between clustered CVD risk score and academic performance in adolescents over a 24-month interval. METHODS: A total of 237 adolescents (45.6% girls), aged 13.9 ± 0.3 years old at baseline, from DADOS (Deporte, ADOlescencia y Salud) study were included in this study. A clustered CVD risk score was created by calculating the mean age- and gender-standardized z-scores of waist circumference, systolic blood pressure, total cholesterol to high-density lipoprotein cholesterol ratio, triglycerides, homeostatic model assessment of insulin resistance, and cardiorespiratory fitness (inversed). Academic performance was assessed through the final academic grades and the test of educational abilities. RESULTS: Our results showed that the clustered CVD risk score at baseline was not associated with academic performance 24 months later (all p > .05). Nevertheless, except for physical education, academic grades at baseline were inversely associated with clustered CVD risk score at follow-up in adolescents (ß ranged from -0.140 to -0.102; all p < .05). No associations were found between academic abilities at baseline and clustered CVD risk score at follow-up (all p > .05). CONCLUSION: Academic grades could help predict CVD risk 24 months later during adolescence. Education professionals should foster adolescents' academic performance not only to improve academic results but also to maximize future cardiovascular health benefits.

Rat hepatitis E virus (Rocahepevirus ratti) in people living with HIV.

Rat hepatitis E virus (ratHEV; species Rocahepevirus ratti) is considered a newly emerging cause of acute hepatitis of zoonotic origin. ratHEV infection of people living with HIV (PLWH) might portend a worse, as with hepatitis E virus (HEV; species Paslahepevirus balayani), and consequently this group may constitute a high-risk population. We aimed to evaluate the prevalence of ratHEV by measuring viral RNA and specific IgG antibodies in a large Spanish cohort of PLWH. Multicentre study conducted in Spain evaluating PLWHIV included in the Spanish AIDS Research Network (CoRIS). Patients were evaluated for ratHEV infection using PCR at baseline and anti-ratHEV IgG by dot blot analysis to evaluate exposure to ratHEV strains. Patients with detectable ratHEV RNA were followed-up to evaluate persistence of viremia and IgG seroconversion. Eight-hundred and forty-two individuals were tested. A total of 9 individuals showed specific IgG antibodies against ratHEV, supposing a prevalence of 1.1 (95% CI; 0.5%-2.1%). Of these, only one was reactive to HEV IgG antibodies by ELISA. One sample was positive for ratHEV RNA (prevalence of infection: 0.1%; 95% CI: 0.08%-0.7%). The case was a man who had sex with men exhibiting a slightly increased alanine transaminase level (49 IU/L) as only biochemical alteration. In the follow-up, the patients showed undetectable ratHEV RNA and seroconversion to specific ratHEV IgG antibodies. Our study shows that ratHEV is geographical broadly distributed in Spain, representing a potential zoonotic threat.

Microwave-Driven Exsolution of Ni Nanoparticles in A-Site Deficient Perovskites.

Exsolution has emerged as a promising method for generating metallic nanoparticles, whose robustness and stability outperform those of more conventional deposition methods, such as impregnation. In general, exsolution involves the migration of transition metal cations, typically perovskites, under reducing conditions, leading to the nucleation of well-anchored metallic nanoparticles on the oxide surface with particular properties. There is growing interest in exploring alternative methods for exsolution that do not rely on high-temperature reduction via hydrogen. For example, utilizing electrochemical potentials or plasma technologies has shown promising results in terms of faster exsolution, leading to better dispersion of nanoparticles under milder conditions. To avoid limitations in scaling up exhibited by electrochemical cells and plasma-generation devices, we proposed a method based on pulsed microwave (MW) radiation to drive the exsolution of metallic nanoparticles. Here, we demonstrate the H2-free MW-driven exsolution of Ni nanoparticles from lanthanum strontium titanates, characterizing the mechanism that provides control over nanoparticle size and dispersion and enhanced catalytic activity and stability for CO2 hydrogenation. The presented method will enable the production of metallic nanoparticles with a high potential for scalability, requiring short exposure times and low temperatures.

Detection of the Uveal Melanoma-Associated Mutation GNAQ Q209P from Liquid Biopsy Using CRISPR/Cas12a Technology.

Uveal melanoma (UM) is a rare ocular tumor characterized by high metastasis risk and poor prognosis. The in-depth characterization of UM's molecular profile is critical for better disease classification and prognosis. Furthermore, the development of detection tools to monitor UM evolution upon treatment is of great interest for designing optimal therapeutic strategies. However, commonly used techniques, such as ddPCR or NGS, are costly, and they involve sophisticated equipment and complex experimental design. The development of alternative sensing methods that are fast, simple, and inexpensive would be of great benefit to improve UM's diagnosis and management, especially when combined with liquid biopsy. Samples from liquid biopsy can be obtained with minimal invasiveness, and the detection of circulating tumor DNA (ctDNA) in UM patients' plasma has proven useful for the diagnosis of metastasis, prognosis prediction, and disease monitoring. In this context, CRISPR/Cas12a-derived molecular sensors, thanks to their high specificity and sensitivity and their potential for point of care diagnosis, are particularly interesting. Here, we developed a CRISPR/Cas12a-based approach for the specific detection of the UM-related mutation GNAQ Q209P that relies on the design of highly specific crRNAs. Coupled with allele-specific PCR, it constitutes a sensitive platform for liquid biopsy detection, capable of sensing GNAQ Q209P in plasma samples with a low ctDNA concentration and fractional abundance. Finally, our method was validated using plasma samples from metastatic UM patients.

Relevance of the anterior cingulate cortex volume and personality in motivated physical activity behaviors.

Some recent theories about the origins and maintenance of regular physical activity focus on the rewards of the properties of practicing this activity. Animal and human studies have demonstrated that mesolimbic dopamine plays a crucial role in the involvement in voluntary physical activity. Here, we test this possible role in a sample of 66 right-handed healthy young adults by studying the influence of personality and the volume of reward-related brain areas on individual differences in voluntary physical activity, objectively measured by accelerometer and subjectively self-reported by questionnaire. Our results show that a smaller volume of the right anterior cingulate cortex and lower scores on reward sensitivity contributed to explaining low levels of daily physical activity. Moreover, the volume of the right anterior cingulate cortex correlates positively with self-reported total physical activity. Results are discussed by highlighting the need to use objective measures of daily physical activity, as well as the important role of the anterior cingulate cortex and personality in promoting effortful and invigorating actions to obtain rewards.

Progressive changes in residual gradient after aortic coarctation repair and its role in the prediction of reintervention: A longitudinal data analysis.

Background: Repair of aortic coarctation through left thoracotomy is the standard treatment when anatomically feasible. Long-term outcomes are well studied, including the need for reintervention. However, the timely variation in residual gradients across the repaired segment is ill-defined. The aim of this work was to study the progressive changes of estimated peak gradient (ePG) acquired by transthoracic continuous-wave Doppler echocardiography across the aortic arch after repair and to assess the role of timing of assessment and values of ePG in prediction of reintervention. Materials and Methods: All eligible patients for this study who underwent aortic coarctation repair through left thoracotomy from 2001 to 2017 were reviewed. Details of the aortic arch dimensions and associated lesions were obtained by transthoracic echocardiography (TTE). The primary outcome was the ePG across the aortic arch after repair. Longitudinal data analyses with mixed effect modeling were used to determine independent predictors for ePGs. Results: A total of 312 patients were included. Median age and weight were 30 days and 4 kg, respectively. Associated lesions included ventricular septal defect (VSD) (53%), bicuspid aortic valve (53%) and mitral stenosis (25%). Over 15-years follow-up the freedom from reintervention was 92.3%, while 24 out of the 312 patients underwent reintervention (7.7%). Longitudinal data analyses of serial 2566 TTE studies were done. The graphical display showed that the ePG across coarctation area in the first postoperative TTE was the most notable difference between those who underwent reintervention and those who did not. Further testing with proportional hazard and logistic regression modeling confirmed this finding. The area under receiver operating curve statistics showed that an ePG of 25 mmHg is an optimal cutoff value for the prediction of the reintervention. Conclusions: The ePG acquired in the first postoperative TTE is the most important predictor for reinterventions. The presence of VSD is associated with decreased ePGs. We propose that an ePG in the first postoperative TTE of 25 mmHg or more is a strong predictor for the need of reintervention.

Observational longitudinal association between waking movement behaviours and psychological distress among adolescents using isotemporal analysis: DADOS study.

This study aimed to examine the impact of reallocating time spent in waking movement behaviours at baseline on indicators of psychological distress at 24-month follow-up using isotemporal substitution regression models among a sample of Spanish adolescents. The DADOS (Deporte, ADOlescencia y Salud) study is a 3-year longitudinal observational research project carried out between years 2015-2017. The analyses included 197 adolescents (91 girls) aged 13.9 ± 0.3 years at baseline. Waking movement behaviours were assessed by a wrist-worn GENEActiv triaxial accelerometer and expressed as minutes/day of light physical activity (LPA), moderate-vigorous physical activity (MVPA) and time spent in sedentary behaviour (SB). The Behaviour Assessment System for Children and Adolescents (level 3 for adolescents) was used to assess psychological distress indicators (i.e., anxiety, social stress, and risk of depression). Results showed significant associations only for girls. The substitution of 10 min/day of SB or LPA at baseline with 10 min/day of MVPA was associated with lower levels of anxiety (both p ≤ 0.01) and social stress (both p < 0.05) at follow-up. The substitution of 10 min/day of SB with 10 min/day of LPA was associated with higher levels of anxiety at follow-up (p = 0.01). These findings highlight the need of specific physical activity recommendations for mental health paying special attention to sex-differences.

Characterization of Latin American migrants at risk for Trypanosoma cruzi infection in a non-endemic setting. Insights into initial evaluation of cardiac and digestive involvement.

BACKGROUND: Trypanosoma cruzi causes Chagas disease (CD), a potentially fatal disease characterized by cardiac disorders and digestive, neurological or mixed alterations. T. cruzi is transmitted to humans by the bite of triatomine vectors; both the parasite and disease are endemic in Latin America and the United States. In the last decades, population migration has changed the classic epidemiology of T. cruzi, contributing to its global spread to traditionally non-endemic countries. Screening is recommended for Latin American populations residing in non-endemic countries. METHODS: The present study analyzes the epidemiological characteristics of 2,820 Latin American individuals who attended the International Health Service (IHS) of the Hospital Clinic de Barcelona between 2002 and 2019. The initial assessment of organ damage among positive cases of T. cruzi infection was analyzed, including the results of electrocardiogram (ECG), echocardiogram, barium enema and esophagogram. RESULTS: Among all the screened individuals attending the clinic, 2,441 (86.6%) were born in Bolivia and 1,993 (70.7%) were female. Of individuals, 1,517 (81.5%) reported previous exposure to the vector, which is a strong risk factor associated with T. cruzi infection; 1,382 individuals were positive for T. cruzi infection. The first evaluation of individuals with confirmed T. cruzi infection, showed 148 (17.1%) individuals with Chagasic cardiomyopathy, the main diagnostic method being an ECG and the right bundle branch block (RBBB) for the most frequent disorder; 16 (10.8%) individuals had a normal ECG and were diagnosed of Chagasic cardiomyopathy by echocardiogram. CONCLUSIONS: We still observe many Latin American individuals who were at risk of T. cruzi infection in highly endemic areas in their countries of origin, and who have not been previously tested for T. cruzi infection. In fact, even in Spain, a country with one of the highest proportion of diagnosis of Latin American populations, T. cruzi infection remains underdiagnosed. The screening of Latin American populations presenting with a similar profile as reported here should be promoted. ECG is considered necessary to assess Chagasic cardiomyopathy in positive individuals, but echocardiograms should also be considered as a diagnostic approach given that it can detect cardiac abnormalities when the ECG is normal.

Individual and combined impact of physical fitness on health-related quality of life during adolescence: DADOS Study.

The purpose of the present study was to investigate the individual and combined impact of physical fitness components at baseline on health-related quality of life (HRQoL) at 24-month follow-up in adolescents. This longitudinal research included 199 adolescents (13.9 ± 0.3 years at baseline) from the DADOS study. Cardiorespiratory fitness was assessed using the 20-m shuttle run test. Muscular strength was assessed using the standing broad jump test. Motor competence was assessed using the 4 × 10-m shuttle run test. A physical fitness z-score was calculated as the mean of the z-scores values of each fitness test. A fitness index ranging from 0 to 3 was created according to the number of physical fitness components in which participants achieved high levels according to normative values. HRQoL was evaluated by the KIDSCREEN-10 questionnaire. Linear regression analyses showed that cardiorespiratory fitness, muscular strength, and the physical fitness z-score at baseline were individually associated with HRQoL at follow-up (ß ranging from 0.123 to 0.183; all p < 0.05). Moreover, logistic regression analysis revealed that adolescents with a fitness index ≥1 at baseline were more likely to achieve high HRQoL at 24-month follow-up, compared with their peers with an index of 0 (OR ranging from 3.554 to 9.087; all p < 0.05). Our results revealed an individual and cumulative positive impact of physical fitness at baseline on HRQoL at 24-month follow-up. These findings underline the key role of promoting the enhancement of overall physical fitness components in order to improve adolescents' health and well-being.Highlights Adolescents with high levels of cardiorespiratory fitness, muscular strength and motor competence will benefit from a greater physical and mental well-being over the time.The more physical fitness components with optimal levels, the greater likelihood of reaching better HRQoL over the time.Public health authorities should focus on the promotion of multiple physical fitness components to increase adolescent's likelihood of achieving greater HRQoL over the time.

The bidirectional longitudinal association between health-related quality of life and academic performance in adolescents: DADOS study.

PURPOSE: Although previous evidence has suggested a relationship between health-related quality of life (HRQoL) and academic performance, the directionality of this association is understudied and remains to be clarified. Thus, the primary objective of this study was to explore the bidirectional association between HRQoL and academic performance in adolescents between two timepoints with a 24-month interval. A secondary aim was to analyze whether this association varies between boys and girls. METHODS: This is a bidirectional longitudinal analysis with 257 adolescents (13.9 ± 0.3 years at baseline) from the DADOS study. HRQoL was measured using the KIDSCREEN-10 questionnaire. Academic performance was assessed through academic grades and the Spanish version of the Science Research Associates Test of Educational Ability. RESULTS: Cross-lagged analyses revealed that HRQoL at baseline was not associated with academic performance 24 months later, while all the academic grades and the overall score of academic abilities at baseline were positively associated with HRQoL at follow-up in adolescents. Results of the stratified analyses by sex were largely similar. Specifically, in girls, math, language, physical education, and grade point average at baseline were positively associated with HRQoL 24 months later, while in boys, all the academic grades indicators (except physical education), numeric ability, and the overall score of academic abilities at baseline were positively associated with HRQoL at follow-up. CONCLUSION: These findings suggest that academic performance in early adolescence may predict HRQoL 24 months later. Health and education professionals could benefit from collaborating to achieve both improved academic performance and HRQoL in youth.

Physical activity and diabetes mortality in people with type 2 diabetes: a prospective cohort study of 0.5 million US people.

AIM: To examine the association between physical activity and the cause of death with the greatest risk related to type 2 diabetes mellitus (T2DM) in a large population-based cohort representative of the general US adult population. METHODS: A total of 41,726 adults suffering from T2DM (age 62 ± 14 years) and 459,660 adults without diabetes (age 46 ± 18 years) who participated in the National Health Interview Survey from 1997 to 2014 were included in this prospective cohort study. Self-reported moderate-to-vigorous physical activity (MVPA) was categorized into inactive, insufficiently active, active and very active. Mortality data was obtained from the National Death Index. Cox regression models adjusted for potential confounders were performed to estimate hazard ratio (HR) and 95% confidence interval (CI). RESULTS: Diabetes mortality cause showed the highest relative risk of death among adults with T2DM compared to adults without diabetes (HR 5.72 [3.15;10.39]). There was a non-linear inverse dose-response association between MVPA and diabetes mortality among adults with T2DM, up to a plateau in risk reduction at approximately 500 min/week. Any level of activity was inversely associated with a significantly lower risk of diabetes mortality compared with being inactive (insufficiently active HR 0.71[0.54;0.97], active HR 0.68 [0.49;0.95], very active HR 0.44 [0.32;0.60]). Compared to adults without diabetes, the risk of diabetes mortality decreased from HR 7.38 [4.00;13.58] for inactive people with T2DM to HR 3.34 [1.76;6.32] for very active people with T2DM. CONCLUSIONS: Higher levels of MVPA were associated with lower risk of diabetes mortality among adults with T2DM.

Risk of depression mediates the association between cardiorespiratory fitness and academic performance in adolescent boys and girls: DADOS study.

This study aims to analyze the mediating role of risk of depression in the association between cardiorespiratory fitness and academic performance in a sample of adolescents and to test the moderation effect of sex. A total of 263 adolescents (125 girls, 13.9 ± 0.3 years) from the DADOS (Deporte, ADOlescencia y Salud) study were included in the analysis. Cardiorespiratory fitness was assessed by the 20-m shuttle run test. Academic performance was assessed through the final academic grades and the test of educational abilities. Risk of depression was evaluated through the Behavior Assessment System for Children and Adolescents. Mediation analyses were performed to determine the direct and indirect associations between cardiorespiratory fitness, risk of depression, and academic performance. Indirect effects with confidence intervals not including zero were interpreted as statistically significant, and percentages of mediation were calculated in order to know how much of the association was explained by the mediation. Our findings indicated a significant mediating effect of risk of depression in the association between cardiorespiratory fitness with final grades in math, language, and grade point average (percentages of mediation: 26%, 53%, and 29%, respectively). These analyses were not moderated by sex (all confidence intervals included 0). CONCLUSION: Risk of depression acts as a possible underlying mechanism in the association between cardiorespiratory fitness and academic grades in adolescents. Educational and health institutions could benefit from our findings since the promotion of higher cardiorespiratory fitness levels might reduce the risk of depression with potential benefits on adolescents' academic performance. WHAT IS KNOWN: • Cardiorespiratory fitness is positively associated with academic performance in adolescents. Nevertheless, the psychological mechanisms underlying this association are poorly understood. WHAT IS NEW: • Risk of depression mediates the association between cardiorespiratory fitness and academic performance in adolescents, independently of sex. • Our findings may improve the efficacy of mental health and educational programs by promoting the enhancement of cardiorespiratory fitness levels, which may reduce risk of depression with potential benefits on academic performance.

A Biomarker Approach as Responses of Bioindicator Commercial Fish Species to Microplastic Ingestion: Assessing Tissue and Biochemical Relationships.

Plastic debris is a growing environmental problem on a global scale, as plastics and microplastics (MPs) can be ingested by marine organisms, inducing toxic effects. The aim of this study was to assess MP intake and antioxidant responses in three bioindicator species: red mullet, bogue, and anchovy (Mullus surmuletus, Boops boops, and Engraulis encrasicolus, respectively) for plastic contamination in the Mediterranean Sea. MP intake was assessed in the gastrointestinal tract of the fish. Further, several enzymes from both the liver and brain were analysed. The antioxidant defences, catalase (CAT) and superoxide dismutase (SOD), as well as the detoxifying enzyme glutathione-S-transferase (GST), were measured in both tissues. The acetylcholine esterase (AchE), as an indicator of neuronal damage, was measured in the brain. Malondialdehyde (MDA) was analysed as a marker of oxidative damage in the brain and liver samples. Total MP intake and MP typology differed between the three species, with M. surmuletus showing the lowest intake of MPs, while B. boops showed the highest intake of MPs. An increase in both antioxidant enzymes was evidenced in E. encrasicolus liver activity with respect to MP intake. In brain samples, an increase in CAT activity was found in M. surmuletus and B. boops as a consequence of MP ingestion. SOD activity in the brain increased in B. boops and E. encrasicolus that had ingested MPs. GST activity increased in the liver of M. surmuletus' and in brains of B. boops that had ingested MPs. The intake of MPs is species related, as well as being inherently linked to the habitat they live in and being able to induce a light activation of species-specific detoxifying and antioxidant mechanisms.

Association between classic and specific bioimpedance vector analysis and sarcopenia in older adults: a cross-sectional study.

BACKGROUND: To verify (1) the association between classic and specific bioelectrical impedance vector analysis (BIVA) with body composition, hydration, and physical performance in older adults with and without sarcopenia; (2) which BIVA most accurately distinguishes sarcopenia. METHODS: A sample of 94 older adults with and without sarcopenia (29 men and 65 women, 60-85 years) was evaluated. The classic and specific BIVA procedures, Dual energy X-ray absorptiometry (DXA), and deuterium dilution were performed. Sarcopenia was defined by muscle weakness and low skeletal muscle index, while severity was indicated by low physical performance. RESULTS: The BIVA's potential to monitor hydration and muscle mass loss in older adults seems feasible. Classic and specific BIVA were able to distinguish sarcopenia in women (p < 0.001), but not in men. When the sarcopenia criteria were individually analyzed, both classic and specific BIVA were able to distinguish low skeletal muscle index in women, while only classic BIVA did for men. For the criterion of slow physical performance, only the classic BIVA showed severity differences for women. The vectors of adults without sarcopenia of both sexes tended to be positioned in the left region of the ellipses, revealing a predominance of soft tissues. CONCLUSIONS: Classic BIVA has a distinct sarcopenic association with body composition, hydration, and physical performance in older adults, while specific BIVA was similar between groups. Both BIVAs are sensible to detect female morphological changes (skeletal muscle index) but not for functional (handgrip, 6-min walk test) sarcopenia criteria. These procedures are promising tools for monitoring sarcopenia risks during aging.

Phylogeography of the veined squid, Loligo forbesii, in European waters.

The veined squid, Loligo forbesii Steenstrup, 1856, occurs at the European Shelf areas including the Azores and represents a valuable resource for the European commercial fishery in the North East Atlantic. However, very little is known about its population structure and phylogeography. This lack of knowledge also impedes the development of sustainable fishery management for this species. The present study combined the use of two types of markers that retrieve patterns of gene flow in different time spans; the analysis of 16 nuclear microsatellites and sequencing of the mitochondrial cytochrome oxidase subunit I (COI). Whereas the high mutation rate of microsatellites allows the description of recent patterns of connectivity in species, the lower mutation rate of COI provides phylogeographic patterns on a longer timescale. A total of 347 individuals of L. forbesii were investigated from nearly the entire distribution range of the species, including the North East Atlantic Shelf, the Azores and the Mediterranean. Individuals from the Western and Eastern Mediterranean Sea have never been included in a genetic study before. We were able to analyse COI sequences from all 12 sampling areas and define three clades of L. forbesii. Due to our large sampling area, we are presenting 13 COI-haplotypes that were previously unknown. The microsatellite analysis does not include the Azores but three main clades could be identified at the remaining 11 sampling sites. Low FST values indicate gene flow over large geographical distances. However, the genetically significant differences and an additional slight grouping in the microsatellite structure reveal that geographical barriers seem to influence the population structure and reduce gene flow. Furthermore, both markers provide strong evidence that the observed phylogeographic pattern reflects the geographical history of the Azores and the Mediterranean Sea.

Single-step hydrogen production from NH3, CH4, and biogas in stacked proton ceramic reactors.

Proton ceramic reactors offer efficient extraction of hydrogen from ammonia, methane, and biogas by coupling endothermic reforming reactions with heat from electrochemical gas separation and compression. Preserving this efficiency in scale-up from cell to stack level poses challenges to the distribution of heat and gas flows and electric current throughout a robust functional design. Here, we demonstrate a 36-cell well-balanced reactor stack enabled by a new interconnect that achieves complete conversion of methane with more than 99% recovery to pressurized hydrogen, leaving a concentrated stream of carbon dioxide. Comparable cell performance was also achieved with ammonia, and the operation was confirmed at pressures exceeding 140 bars. The stacking of proton ceramic reactors into practical thermo-electrochemical devices demonstrates their potential in efficient hydrogen production.

CASCADE: Naked eye-detection of SARS-CoV-2 using Cas13a and gold nanoparticles.

The COVID-19 pandemic has brought to light the need for fast and sensitive detection methods to prevent the spread of pathogens. The scientific community is making a great effort to design new molecular detection methods suitable for fast point-of-care applications. In this regard, a variety of approaches have been developed or optimized, including isothermal amplification of viral nucleic acids, CRISPR-mediated target recognition, and read-out systems based on nanomaterials. Herein, we present CASCADE (CRISPR/CAS-based Colorimetric nucleic Acid DEtection), a sensing system for fast and specific naked-eye detection of SARS-CoV-2 RNA. In this approach, viral RNA is recognized by the LwaCas13a CRISPR protein, which activates its collateral RNase activity. Upon target recognition, Cas13a cleaves ssRNA oligonucleotides conjugated to gold nanoparticles (AuNPs), thus inducing their colloidal aggregation, which can be easily visualized. After an exhaustive optimization of functionalized AuNPs, CASCADE can detect picomolar concentrations of SARS-CoV-2 RNA. This sensitivity is further increased to low femtomolar (3 fM) and even attomolar (40 aM) ranges when CASCADE is coupled to RPA or NASBA isothermal nucleic acid amplification, respectively. We finally demonstrate that CASCADE succeeds in detecting SARS-CoV-2 in clinical samples from nasopharyngeal swabs. In conclusion, CASCADE is a fast and versatile RNA biosensor that can be coupled to different isothermal nucleic acid amplification methods for naked-eye diagnosis of infectious diseases.

Development of colorimetric sensors based on gold nanoparticles for SARS-CoV-2 RdRp, E and S genes detection.

We present a fast, reliable and easy to scale-up colorimetric sensor based on gold nanoparticles (AuNPs) to detect the sequences coding for the RdRp, E, and S proteins of SARS-CoV-2. The optimization of the system (so-called "the sensor") includes the evaluation of different sizes of nanoparticles, sequences of oligonucleotides and buffers. It is stable for months without any noticeable decrease in its activity, allowing the detection of SARS-CoV-2 sequences by the naked eye in 15 min. The efficiency and selectivity of detection, in terms of significative colorimetric changes in the solution upon target recognition, are qualitatively (visually) and quantitatively (absorbance measurements) assessed using synthetic samples and samples derived from infected cells and patients. Furthermore, an easy and affordable amplification approach is implemented to increase the system's sensitivity for detecting high and medium viral loads (≥103 - 104 viral RNA copies/µl) in patient samples. The whole process (amplification and detection) takes 2.5 h. Due to the ease of use, stability and minimum equipment requirements, the proposed approach can be a valuable tool for the detection of SARS-CoV-2 at facilities with limited resources.

Diet and feeding behaviour of albacore Thunnus alalunga in the western Mediterranean Sea during the spawning period.

Mature albacore tuna (Thunnus alalunga) are expected to have high energy requirements at the time of breeding. However, there are no descriptions of the diet of albacore in the Mediterranean Sea that can help us to understand if such requirements can be obtained from feeding during reproduction. In this study, we analysed the stomach contents of reproductively active albacore captured from 2010 to 2015 in the oligotrophic waters of the western Mediterranean Sea, one of their main spawning grounds. Estimates of stomach fullness revealed intense feeding activity, and prey composition indicated important consumption of mesopelagic fish, including barracudinas, myctophids and small pelagic crustaceans. Plastic debris occurred in 25%-53% of the stomachs sampled across all years. Prey composition was not different between males and females. However, females fed at higher rates and had higher hepatosomatic index values than males, suggesting that increased feeding could contribute to meet their higher energy demand associated with offspring production. We observed a diet shift from small crustaceans to fish prey along fish size. During the spawning period, albacore showed a specialist feeding behaviour by preying on aggregations of vertically migrating myctophids and small crustaceans, probably when they were near the surface. This study provides information and biological data to support ecosystem modelling and to increase the understanding of albacore ecology.